1. Field of the Invention
The invention is related to the fields of viral vectors for targeted gene therapy and pharmaceutical preparations, and more particularly to viral vectors for tumor therapy.
2. Description of the Related Art
The ability to deliver recombinant molecules to specific cells or tissues has been a long term goal of pharmaceutical therapeutics and gene therapy. Viruses and virus based vectors represent a powerful tool for these purposes, due to the efficiency of infection compared to other delivery systems and the high level of expression of recombinant molecules.
A distinct and widely recognized limitation of current virus-based delivery systems has been the lack of success in targeting these recombinant viruses to predetermined cell types or tissues. Thus, the enormous potential of viruses as delivery agents for pharmaceutical or gene therapy has been overshadowed by a technical roadblock, the inability of an infection by a recombinant virus to be specifically targeted and limited to a predetermined population of cells, a challenge termed "selective toxicity" (Nolan, 1997). There is a need, therefore, for a novel gene delivery system that provides a simple and flexible general method to overcome this limitation in controlling cell targeting by a recombinant virus.